Petersborggata 11 is one of the smallest houses in the street, but it still has the same basic square footprint with a central chimneystack. The house was completed in 1923. Stories told by the owner suggest that the first owner had to work at Spitsbergen for a year to afford to have it built. It has no dormers, but part of the roof is lifted on the eastern side. It also still has both the original slate roof and roof window.